Press



June 17, 1969 R. PETERSON 3,450,031

PRESS Filed Nov. 10. 1966 INVENTOR.

POY LP mw/v United States Patent 3,450,031 PRESS Roy L. Peterson, 73Wildwood Beach Road, Mahtomedi, Minn. 55115 Filed Nov. 10, 1966, Ser.No. 593,489 Int. Cl. 1330b 15/34 US. Cl. 100-93 2 Claims ABSTRACT OF THEDISCLOSURE This invention relates primarily to the protection andpreservation of rare coins, and more particularly to apparatus forhermetically sealing such coins within transparent plastic filmenvelopes, where they remain fully protected from abrasion andcontamination while remaining entirely visible.

The apparatus is in the form of a hand-operated press. The coin,desirably in clean and untarnished condition, is inserted in a smallopen-top transparent plastic envelope, for example of thin polyethylenefilm, which is placed between the platens of the press. The press isclosed by means of a compound lever system. The two opposing resilientlycompressible platens force the two sides of the envelope tightly againstthe enclosed coin or against each other, while expelling essentially allof the initially enclosed air through the open end. Momentary pressureon a control button then activates a heater unit to cause heatsealing ofthe envelope across its end. The platens are then separated and thecoin, in its protective sealed envelope, is removed.

The apparatus is illustrated in the appended drawing, in which FIGURE 1is a view in perspective from one side of the apparatus with the platensin open position,

FIGURE 2 is a similar view from the opposite side and with the platensin closed position, and

FIGURE 3 is a top plan view, and FIGURE 4 a side elevation, withportions removed, showing details of the heat-sealing unit.

The apparatus of FIGURES 1 and 2 consists of a base 11 and hollow cover12 on which are mounted a pushbutton 13, lower platen 14, lever 15, andtransformer 16. The lower platen includes a pan 18, pad 19, and heatingunit 20. An upper platen 21, consisting of a pan 22 and pad 23, is movably attached to the lower pan 18 by means of a hinge 24. A rod 25fastened across the pan 22 is connected to the side arms of the invertedU-shaped lever by connecting links 26. The lever 15 is supported at theends of its side arms on pins 27 extending from opposite side edges ofthe cover 12. A crosspiece 28 reinforces the lever 15 and also serves asa stop to hold the lever with the platens in fully closed condition.

The heating unit 20, shown in more detail in FIGURES 3 and 4, consistsof an insulating block 30 perforated near each end to receive connectingand supporting prongs 31 between which extends a resistance wire 32. Theprongs 31 are frictionally retained Within the block 30 but may beforcefully removed and replaced when necessary, as in the replacement ofthe wire 32. The prongs make connection at their extended ends withsuitable receptacles, not shown, Within the cover 12, thus permittingeasy removal and replacement of the entire unit 20.

The resistance wire, and the top and upper side edges of the block 30,are covered with a flexible strip 33 of heat-resistant protective sheetmaterial, of which a preferred example is glass fabric reinforced Teflonpolytetrafluoroethylene film pressure-sensitive adhesive tape. The tapeis easily applied and as easily removed. It is heat-resistant, yet issufiiciently heat-conductive to permit rapid heating of the plasticenvelope; and the heat-softened envelope does not adhere to the surfaceof the film. The adhesive holds the film in smooth close conformity withthe upper surface of the block 30 and with the exposed resistance Wire32.

The pads 19, 23 are of a firm grade of resilient rubbery syntheticsponge. They extend sufliciently beyond the rim of their respective pansto provide strong pressure against each other as the lever 15 is broughtto the closed position, but are sufiiciently resilient and compressibleto accept both thick coins and thin sheets of plastic between them whenthus pressed together. They fit closely within their respective pans,which in turn prevent the pads from expanding laterally when undercompression and thus assure uniformity of pressure. The upper surface ofthe heater unit 20 is somewhat below the upper level of the pad 19 andmay be aligned with, or slightly above, the top edge of the pan 14, theupper pad 23 providing fully adequate pressure to assure removal of airand hermetic sealing of envelopes along the heater area.

The heater element is connected in series with the pushbutton switch 13and the secondary of the transformer 16, the primary of which isconnected to a source of power through the cord 34. The use of atransformer provides for high efiiciency without overheating of theapparatus; but other means for controlling the voltage at the resistanceWire 32, such for example as additional resistors, may be substituted.

A short heating period of no more than one or two seconds is ordinarilyadequate to cause the formation of a hermetic seal across the previouslyopen end of the plastic envelope, particularly where the latter is ofthin polyethylene film or the like. Timing of such short periods iseasily accomplished with adequate precision without mechanicalassistance, and the push-button 13 is entirely sufficient and providesmaximum convenience for such operations, although automatic timing andshutoff means may be added if desired.

It is ordinarily found desirable to allow a brief cooling period beforeopening the press and removing the sealed coin, so that the seal line ofthe envelope may first cool somewhat and be fully resistant to anytearing action arising during the opening and removal operation.Sticking and tearing of the envelope are also avoided by the use ofadhesion-resistant coverings such as the adhesive tape 33, as previouslynoted.

What is claimed is as follows:

1. A press suitable for use by coin collectors and nu-mismatists forrapidly and conveniently sealing coins within small transparentprotective plastic envelopes, said press consisting essentially of: abase; opposing pressure platens each having a resiliently compressiblesurfiace, said platens being hingedly connected together along one side,one of said platens containing a heater element closely adjacent theside opposite the hinge and being fastened to said base; lever means forclosing and opening said press (fastened to said base and consisting ofan open frame having the general shape of an inverted U, a bearing barand a stop bar connecting the two legs of the U at approximately theircenters, and a pair of connecting links suspended from said bearing barand attached at their opposite ends to the upper platen member of saidpress; and control means for actuating and deactuating said heaterelement.

platen comp-rises a resiliently compressible pad within an enclosingopen-faced pan.

References Cited UNITED STATES PATENTS 1,402,433 1/1922 Monroe 100-2332,496,609 2/ 1950 Van Antwerpen 53-373 X 2,557,975 6/1951 King 100-93 X2,644,151 6/1953 Krueger 10093 3,106,630 10/1963 Klamp l00--93 PETERFELDMAN, Primary Examiner.

US. Cl. X.R.

' 2. A press according to claim 1 wherein each said 15 100-233, 281

